Refrigerating apparatus



July 18, 1950 1.. A. PHILIPP 2,515,526

REF'RIGERATING APPARATUS Filed Jan. 16, 1946 2 Sheets-Sheet 1 INVENTOR. Lflh/EEME A. PHIL IPP Patented July 18, 1950 UNITED STATES PATENT OFFICE BEFRIGERATING APPARATUS Lawrence A. Philipp, Detroit, Micln, assignor to Nash-Kelvinator Corporation, Detroit, Micln, a

corporation of Maryland Application January 16, 1946, Serial No. 641,465

3 Claims. 1

The present invention relates to refrigerating apparatus and more particularly to refrigerators of the two temperature type.

One of the objects of the present invention is to provide within a refrigerator cabinet an improved arrangement for maintaining a relative high humidity and low temperature for the preservation of foodstuffs.

Another object of the present invention is to provide within a refrigerator 9. primary and a secondary cooling system; the primary system including two spaced apart refrigerant evaporators separated by an adjustable pressure differential device, and to utilize one of said evaporators for condensing evaporated refrigerant in the secondary system.

Another object of the present invention is to provide within a refrigerator cabinet a plurality of spaced apart imperforate shelves, preferably made of transparent glass, which are slightly spaced from one wall of the compartment so as to provide a fixed path for the circulation of air above, below and between the shelves, a relatively low temperature refrigerant evaporator for cooling the space above the shelves and an additional refrigerant evaporator for cooling the space within the vicinity of the shelves, preferably through a wall of the food storage compartment without the collection of frost and ice on that wall at least part of the time, and to provide for increasing the temperature of said additional refrigerant evaporator to induce an increased air circulation towards the relatively low temperature evaporator through the fixed passages so that excess moisture is removed by the refrigerating effect of the relatively low temperature evaporator.

Another object of the present invention is to provide a refrigerating system having a variable temperature refrigerant evaporating element for cooling a portion of a food storage compartment so as to maintain relative high humidity therein, and a refrigerant evaporator element used primarily for freezing substance, having insufflcient capacity to cool the entire food storage compartment, for removing excess moisture from the portion of the compartment where relative high humidity is maintained.

Another object of the present invention is to provide an improved arrangement whereby the user may adjust the refrigerating means to control the relative humidity in a food storage compartment.

Further objects and advantages of the present nvention will be apparent from the following description, reference being had to the accompanying drawings. wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a side view with parts broken away and parts shown in cross section of a refrigerator cabinet embodying features of the present invention;

Fig. 2 is a fragmentary enlarged view of the rear portion of the ice making refrigerant evaporator and the heat exchange relationship between the primary and secondary refrigerating systems;

Fig. 3 is a cross-sectional view taken along line 3-3 of Fig. 2; and

Fig. 4 is a diagrammatic illustration of a refrigerating system embodying features of my invention.

Shown in the drawing is a refrigerator cabinet 20 formed with an outer sheet metal casing 22 and an inner sheet metal liner 24 between which is interposed suitable heat insulation material 26 thereby forming insulated top, side and back walls for the cabinet. The outer metal casing is extended to form a machine compartment 21. The inner metal liner 24 forms the walls of a food storage compartment 30 which is insulated from the machine compartment by insulation material 32.

A suitable door 34 is provided for closing the opening to the food storage compartment, and a closure member 36 for closing the opening to the machine compartment. The closure member 36 is provided with a vegetable bin 31 projecting into the machine compartment having an inclined rear wall to which is secured an insulated pad 39.

Positioned within the food storage compartment is a refrigerant evaporating element 40 consisting of sheet metal material formed to provide a structure in a general shape of a c which constitutes the refrigerant containing walls of the element and includes an upper horizontally positioned shelf portion 42 and a lower horizontally positioned shelf portion 44 connected by a perpendicular portion 46 which includes a header 41. The vsides are enclosed by sheet metal material 49 which has formed integrally therewith a'rear portion 50. The side walls, as well as the rear portion 50, extend above the upper shelf portion, and secured thereto are brackets for securing the element in supporting relation to the top wall of the liner by bolts 52. A door 54 may be used for closing the front of the evaporating element 40. Carried by the sheet metal mathrough the serpentined passage formed by the on each side of the element 40. These members are joined by cross wire members (not shown) which are utilized for supporting drip pan 56 immediately below the evaporator. The U- shaped members extend downwardly below the cross wires and provide guides for guiding receptacle 51 when it is positioned beneath the element on shelf 60.

Positioned within the food storage compartment are a plurality of vertically spaced shelves 60, 62 and 64. The shelves are preferably constructed of transparent glass so as to provide tnansparent imperforate shelf structures. If desired, these shelves may be constructed of sheet metal, plastic or other materials. When the shelves are constructed of glass, angular metal strips 65 are provided along the front edges so as to protect the front edge of the shelf against breakage by contact therewith upon placing foodstufis in the refrigerator. The shelves 60 and 62 are of the same size and shape and are supported by brackets 61 carried by the liner 24. These shelves extend substantially from one side of the liner to the other and from substantially the front part of the food storage compartment to a point adjacent the rear wall of the liner to provide a space 69 at the rear of each shelf between the rear edges and the rear wall of the liner limiting circulation of air through the spaces 69. Shelf 64 is preferably formed in two sections extending between the side walls of the liner and are similarly supported by brackets 61 (not shown) along the side walls of the liner. The inner adjacent ends of each section are supported by a bracket having a horizontal portion and a vertical portion 12. The horizontal portion 10 is secured to the rear wall of the liner, and the vertical section is secured by bolt to the bottom wall of the liner. The front edge of the sections of shelf 64 are spaced from the front of the cabinet to provide space for doors 14. The doors 14 serve to close the lower portion of the cabinet extending from the shelf 62 to the bottom wall of the liner. These doors are hingedly mounted b hinges 15 to the side walls of the liner and are preferably con-- structed of transparent glass so that foodstuffs stored therebehind may be readily visualized from the front of the cabinet. The shelf 64 together with the doors 14 provide What is hereinafter termed as high humidity compartment, designated in general by the numeral 11. This compartment includes the space above as well as the space below the shelf 64. The rear edge of the shelf 64 is also spaced from the rear wall of the liner limiting air circulation from above and below the shelf through space 69.

In order to cool the high humidity compartment 11 there is provided a secondary refrigerating system, designated in general by the numeral 90. The system includes an evaporator 92 which is in the form of serpentine coil and is secured to the bottom wall and the rear wall of liner by bracket 94. The coil also extends along the lower portion of the side walls of the liner (not shown). The evaporator is operatively connected to a condenser 96. The condenser consists of a tank 91 which is in open communication with both ends of the evaporator. Inlet end I00 of the evaporator 92 is positioned adjacent the lower portion of the tank 91 and the outlet end I02 of the evaporator is positioned near the upper end of the tank 91. By this arrangement, liquid refrigerant which is condensed in tank 91 enters end I00 of the evaporator whence it flowsevaporator 92, and the evaporated refrigerant passes out the outlet end I02,into the tank to be condensed. The inlet end I00 of the evaporator 92 includes a vertically extending portion I04 which passes over a portion of the evaporator secured to the rear wall of the liner. To prevent the transfer of heat from leg I04 to the horizontally extending portions of the evaporator on the rear wall of the liner, there is placed a piece of insulating material I06 therebetween. The secondary evaporator 92, in addition to being secured to the liner by bracket 94, is also secured thereto by a coatingof bituminous cement I01 to insure good contact between evaporator 92 and the liner 24. The evaporator 92 is adapted to absorb heat from the circulating air in the high humidity compartment 11 by absorbing the heat through the liner 24 and is adapted to cool the compartment 11 without the collection of frost on the liner.

Liquid refrigerant is delivered to the evaporating element 40 by a refrigerant liquifying and condensing element IIO disposed within the machine compartment 21 which is open at the rear thereof, and at the bottom thereof for air circulation therethrough. The element includes motor compressor unit I I2 and condenser II4 secured to and carried by base I I6. The condenser is horizontally positioned on a slight angle below the motor compressor unit. The condensing element IIO delivers liquid refrigerant to the avaporator element 40 through a small diameter or capilary tube II 1. Before the refrigerant leaving the small diameter tube II1 enters the evaporating element 40 it passes through a refrigerant evaporating or heat exchange portion I20. This portion I20 is wrapped around the tank 91 and is held in good thermal contact therewith by means of a clamped sleeve I22 which SlllI'OllIldS the evaporating portion I20 and clamps it to the tank 91. The ends of the sleeve I22 are clamped together by bolts I24. The portion I20 and tank 91 are positioned in the insulation between the inner liner and the outer casing. The refrigerant after leaving the evaporating portion I20 then passes through conduit I26 into an inlet I21 of the evaporating element 40. Interposed between the evaporating portion I20 and evaporating element 40 in the conduit I26 is a manually operated throttling valve I30. Evaporated refrigerant is withdrawn from the evaporating element 40 into a vapor return conduit I32 which is placed in heat exchange relation with the small diameter tube II1 where the cool gases in the return conduit I32 cool the conduit so that it tends to cool the liquid refrigerant passing through the small diameter tube I I1. The small diameter tube H1 and inlet conduit I26 are preferably covered by a soft rubber insulating material I28 so as to prevent the formation of moisture on the insulation of the cabinet. The clamping sleeve I22 is covered by insulation I34 which in turn is covered by a rubber enclosure I36. At the lower portion of the clamping sleeve I22 is a rubber disc I31 which is split for receiving conduits II1, I26, I00 and I02. The rubber cover or enclosure I36 is secured to the disc by a clamp I39. Preferably, the disc I31 is sealed at I38 where it is split, by sealing material, such, for example as asphaltie cement. Likewise alphaltic cement may be used around the peripheral edge of the disc I31 to seal it to the rubber cover I36; Thus, an airtight seal is provided around the tank 91 and evaporating moisture upon the cold surfaces thereof to thus prevent any likelihood ofmoisture getting into the insulation at times when the system is not operating.

The operation of the system is as follows. Gaseous refrigerant is withdrawn from the refrigerant evaporating element 40 through vapor return conduit I32 whence it passes to the motor compressor unit II2 which compresses it and delivers it to the condenser II4. The refrigerant is liquefied in the condenser H4 and delivered to the evaporating element under the control of small diameter tube III. Any suitable control device, such as a thermostatic element I I8 having a bulb II9 attached to evaporating element 40 to cause said thermostatic element I I8 to be responsive to changes in temperature of the evaporating element 40 orsheet metal side walls 49 thereof, may be used for controlling the operation of the motor compressor unit. Preferably the evaporating element 40 is operated at sufficiently low temperatures for freezing ice in receptacles (not shown) placed upon shelf portions 42 and 44, or in receptacles placed upon a removable intermediate shelf I4'I secured between shelf portions 42 and 44. The liquid refrigerant prior to entering the evaporator element 40 flows through the evaporating portion I20 which surrounds the tank or secondary condenser 91. The cooling effect of the refrigerant evaporating in the portion I20 liquefies gaseous refrigerant in the tank 91. The liquid refrigerant in tank 91 then flows down into the secondary refrigerant evaporator 92 and as it gasifies passes through the outlet end I02 into the tank 91 where it is again liquefied. Preferably, the evaporating portion I20 is of such area as to cause the tank 91 to serve its condensing function in such manner that the evaporator 92 operates at sufficiently low enough temperature to properly cool the compartment ll to the desired temperature for preserving foodstuffs stored therein. However, due to the size of portion I20 and due to the bituminous cement around the evaporator 02 and the contact with the liner where it is secured thereto, the liner absorbs heat from the compartment 11 without the collection of frost or ice at least part of the time, upon the inner walls of the liner 24. By dividing off the compartment 30 so as to provide a high humidity compartment 11 and cooling the same by secondary refrigerant by the evaporator 92 it is possible to store fresh vegetables in the compartment 1'! where they will be kept in fresh condition for long periods of time. In actual practice it has been found that the temperature in the humid compartment is somewhat lower than the temperature immediately above compartment TI because of the small effective cooling area of the refrigerant evaporating element 40. As shown, the refrigerant evaporating element 40 has a refrigerant containing bottom wall and rear wall only exposed to the circulating air within the food storage compartment 30. In addition the drip pan 56 is positioned immediately below the bottom wall 42 of the element 40 which prevents, to a certain extent, contact of the circulating air with the bottom wall of the evaporating element. Un-

der these conditions, the refrigerant evaporating compartment, and particularly the compartment I1, the air is confined in its circulation within. the compartment 'II being cooled by its contact with the refrigerated walls of the liner resulting in a very high relative humidity and of such high value that the vegetables retain their original crispness over long periods of time. Because the compartment I1 is lower in temperature than the food storage compartment immediately above the shelf 62, the air circulation will be confined within the compartment with very little circulation through the passage 69 upwardly along the rear wall of the liner 24 to come into contact with the refrigerant evaporator element 40 to freeze out moisture from the circulating air on the surface of the evaporating element 40. Under these conditions the fresh vegetables and the like stored in the high humidity compartment will not lose their moisture by diffusion.

However, on very humid days too much moisture may form in the compartment I1 and collect on the walls of the liner and flows downwardly to collecton the bottom wall of the liner and compartment 11. To prevent collection of excess moisture and to effect a drying of the compartment 11 of this excess collected moisture, there is provided the manually operated throttling valve I30 for controlling the flow of refrigerant from the evaporating portion I20 to the evaporator element 40 through conduit I26. The valve is shown positioned behind the evaporator element 40 requiring the user to reach around the element 40. It will be obvious that it may be located in any suitable location accessible to the user of the refrigerator, either below the element 40, adjacent to the side wall of the element, or carried to a front panel of the element 40. The valve I30 normally is in fully opened position. When in normal or fully opened position the orifice of the valve is equal to the diameter of the conduit I26 so that the sole control device for controlling the flow of refrigerant to the evaporating portion I20 and evaporating element 40 is the small diameter tube Ill. By a partial closing of the valve the flow of refrigerant would be further restricted through the conduit I26 into the evaporating element 40. This restriction tends to create a variation of refrigerant pressure, with an increase in pressure in the evaporating portion I20, and a decrease in refri erant pressure in the evaporating element 40. By increasing the refrigerant pressure in the evaporator portion I20 there is effected a decrease in the rate of liquefying the gaseous refrigerant in the tank 91 resulting in an increase in the temperature of the secondary refrigerant evaporator and a resulting increase in the temperature of the air in the compartment 11. By increasing the temperature of the air in compartment 11 there is an increase in the rate of air circulation from the compartment 11 towards the low temperature evaporator element 40. The circulation of air upwardly from the warmer compartment I1 to the colder portion of the food storage compartment above the shelf 62 comes into contact with the low temperature refrigerant evaporator element 40 and will freeze out such excess moisture in the surfaces of the refrigerant evaporating element as to prevent the accumulation of excess moisture upon the bottom wall of the refrigerant liner.

By providing a manually controlled throttling valve the user may continue to operate the refrigerating system until all the excessive moisture is removed from the compartment 11 and 7 deposited as frost upon the refrigerant evaporating element, or until suflicient drying out of the compartment is had upon which the valve may be again fully opened to permit normal refrigeration. During normal operation the accumulated frost is defrosted from the refrigerant evaporating element 40 during the off-cycle of the refrigerating system, the moisture being collected in the tray 56. By this arrangement the user may control the moisture contents of the air within the food storage compartment without necessitating the removal of any article of food therefrom. The food storage compartment being maintained at a temperature sufficiently low for the preservation of foodstuffs, the valve I30 merely causing by a pressure differential a variation of temperature difference between the upper and lower portions of the food storage compartment making the portion above the shelf 12 colder so as to increase the air circulation from the warmer compartment I1 to the colder portion above the shelf I2 so that the air will contact the refrigerant evaporating element 40 for the freezing out of excessive maisture from the air.

The throttling valve I30 may be any of the well known hand operated throttling valves. Preferably the valve is of that type wherein the orifice may be gradually closed by the operation of a hand wheel to permit variable adjustments, though it will appear abvious that it may be of the plunger type having a fixed small orifice, and a larger orifice. The plunger operating to close the larger orifice and by-pass the refrigerant through the smaller orifice. The plunger may be operated, if desired, electro-magnetically and controlled by means of a humidistat (not shown) and suitably located within the compartment 11.

Preferably, the evaporating element 40, the evaporating portion I20 and the condensing unit III which constitute the primary refrigerating system are removed from the cabinet as a unitary structure without disconnecting the conduits I I1, I32 and I26 when it is desired to remove the primary refrigerating system from the cabinet for repairs. The secondary refrigerating system remains within the cabinet as it is unnecessary to remove same as it includes no moving parts necessitating repairs. When it is desired to remove the primary refrigerating system, all that is necessary is to remove the flue I60 from the cabinet, remove removable panel I62 on the rear of the cabinet at the back of the evaporating element 40, then remove the removable panel I64 adjacent the rear of the evaporating element 40 with the insulation material therebetween. Then disconnect the evaporating portion I20 from the secondary condenser or tank 01. The liner 24 is provided with an opening lit in its rear wall for removal or insertion therethrough of the evaporating element 40 and is closed by the panel I64.

While I have shown and described the preferred form of my invention, I do not wish to limit myself to the precise details as shown and described, but wish to avail myself of such variations and modifications as may come within the scope of the appended claims.

50 Number I claim:

1. Refrigerating apparatus comprising a cabinet having two adjacent ciimpartments arranged to allow restricted air flow therebetween, means operable to freeze substances in the upper one of said compartments and to freeze out moisture from the circulating air in said compartments, air cooling means for cooling the air in the lower one of said compartments to a sufficiently low enough temperature that the flow of air therefrom to said upper compartment is limited and movable valve means for modifying the effectiveness of said air cooling means.

2. Refrigerating apparatus comprising a cabinet having two adjacent compartments arranged to allow restricted air flow therebetween, means operable to freeze substances in the upper one of said compartments and to freeze out moisture from the circulating air in said compartments, air cooling means for cooling the air in the lower one of said compartments to a sufliciently low enough temperature that the flow of air therefrom to said upper compartment is limited and movable valve means operable to increase the temperature of said air cooling means to increase the air flow between said compartments without affecting the area through which the air must flow from one compartment to the other.

3. Refrigerating apparatus comprising a primary refrigerating system including a relatively large ice making refrigerant evaporator and a relatively small evaporator connected in series circuit relationship and being arranged so that the relatively small refrigerant evaporator is the first to receive refrigerant, a condensing element operatively connected with said evaporators, a. secondary refrigerating system including a refrigerator evaporator and a secondary condenser with the secondary condenser connected in heat exchange relation with said relatively small evaporator, a movable refrigerant flow control valve connected in said primary refrigerating system between the icemaking evaporator and the relatively small evaporator, and means for controlling the operation of said condensing element in response to changes in temperature of said relatively large ice making evaporator, said valve being arranged to be operable to increase the temperature in said relatively small evaporator throughout part or all of the operating phase of the refrigerating cycle of said primary system.

LAWRENCE A. PHILIPP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 2,133,958 2,207,125 2,361,792 2,387,840 2,452,685

Kuebler et al July 9, 1940 Phillip Oct. 31, 1944 Gifford Oct. 30, 1945 Rodoy Nov. 2, 1948 Kalischer Oct. 25,1938

Certificate of Correction Patent No. 2,515,526 July 18, 1950 LAWRENCE A. PHILIP]? It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 33, for avaporator read evaporator; line 34, for capilary read capillary; line 72, for alphaltid read asphaltic; column 7, line 24, for maisture read moisture; line 30, for abvious read obvious; column 8, lines 38 and 39, for refrigerator read refrigerant; and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 10th day of October, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

